package com.learn.common.interceptors;


import com.auth0.jwt.exceptions.JWTDecodeException;
import com.learn.common.annotation.PassToken;
import com.learn.common.annotation.UserLoginToken;
import com.learn.common.utils.JwtUtil;

import com.learn.core.domain.LUser;
import com.learn.core.service.ILUserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.method.HandlerMethod;

import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;
import java.lang.reflect.Method;


/**
 * @author jinbin
 * @date 2018-07-08 20:41
 */
public class AuthenticationInterceptor implements HandlerInterceptor {
    @Autowired
    ILUserService userService;
    @Override
    public boolean preHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object object) throws Exception {
        String token = httpServletRequest.getHeader("token");// 从 http 请求头中取出 token
        // 如果不是映射到方法直接通过
        if(!(object instanceof HandlerMethod)){
            return true;
        }
        HandlerMethod handlerMethod=(HandlerMethod)object;
        Method method=handlerMethod.getMethod();
        //检查是否有passtoken注释，有则跳过认证
        if (method.isAnnotationPresent(PassToken.class)) {
            PassToken passToken = method.getAnnotation(PassToken.class);
            if (passToken.required()) {
                return true;
            }
        }
        //检查有没有需要用户权限的注解
        if (method.isAnnotationPresent(UserLoginToken.class)) {
            UserLoginToken userLoginToken = method.getAnnotation(UserLoginToken.class);


            if (userLoginToken.required()) {
                // 执行认证
                if (token == null) {
                    String str = "{\"state\":1001,\"msg\":\"无法找到授权信息\"}";
                    dealErrorReturn(httpServletRequest, httpServletResponse, str);
                }
                boolean b = JwtUtil.verify(token);
                if(!b) {
                    String str = "{\"state\":1001,\"msg\":\"授权已过期，请重新登录\"}";
                    dealErrorReturn(httpServletRequest, httpServletResponse, str);
                }

                // 获取 token 中的 user id
                String userId = null;
                try {
                    userId = JwtUtil.getUserId(token);
                } catch (JWTDecodeException j) {
                    String str = "{\"state\":1001,\"msg\":\"无效的授权\"}";
                    dealErrorReturn(httpServletRequest, httpServletResponse, str);
                }
                if(userId==null){
                    String str = "{\"state\":1001,\"msg\":\"无效的授权\"}";
                    dealErrorReturn(httpServletRequest, httpServletResponse, str);
                }
                LUser user = userService.getById(Integer.parseInt(userId));
                if (user == null) {
                    String str = "{\"state\":1001,\"msg\":\"无效的授权\"}";
                    dealErrorReturn(httpServletRequest, httpServletResponse, str);
                }
                // 验证 token

                return true;
            }
        }
        return true;
    }

    @Override
    public void postHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, ModelAndView modelAndView) throws Exception {

    }
    @Override
    public void afterCompletion(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) throws Exception {

    }

    public void dealErrorReturn(HttpServletRequest request, HttpServletResponse response, Object obj) {

        String json = (String) obj;
        PrintWriter writer = null;
        response.setCharacterEncoding("UTF-8");
        response.setContentType("application/json; charset=utf-8");
        try {
            writer = response.getWriter();
            writer.print(json);
        } catch (IOException ex) {
        } finally {
            if (writer != null) {
                writer.close();
            }
        }
    }
}